Server: enable lookup decoding

Makefile

@@ -800,7 +800,7 @@ save-load-state: examples/save-load-state/save-load-state.cpp ggml.o llama.o $(C
 	$(CXX) $(CXXFLAGS) -c $< -o $(call GET_OBJ_FILE, $<)
 	$(CXX) $(CXXFLAGS) $(filter-out %.h $<,$^) $(call GET_OBJ_FILE, $<) -o $@ $(LDFLAGS)
 
-server: examples/server/server.cpp examples/server/utils.hpp examples/server/httplib.h common/json.hpp examples/server/index.html.hpp examples/server/index.js.hpp examples/server/completion.js.hpp common/stb_image.h ggml.o llama.o $(COMMON_DEPS) grammar-parser.o $(OBJS)
+server: examples/server/server.cpp examples/server/utils.hpp examples/server/httplib.h common/json.hpp examples/server/index.html.hpp examples/server/index.js.hpp examples/server/completion.js.hpp common/stb_image.h ggml.o llama.o ngram-cache.o $(COMMON_DEPS) grammar-parser.o $(OBJS)
 	$(CXX) $(CXXFLAGS) -c $< -o $(call GET_OBJ_FILE, $<)
 	$(CXX) $(CXXFLAGS) $(filter-out %.h %.hpp $<,$^) -Iexamples/server $(call GET_OBJ_FILE, $<) -o $@ $(LDFLAGS) $(LWINSOCK2)
 

common/ngram-cache.cpp

@@ -216,12 +216,11 @@ void llama_ngram_cache_save(llama_ngram_cache & ngram_cache, std::string & filen
 
 }
 
-llama_ngram_cache llama_ngram_cache_load(std::string & filename) {
+bool llama_ngram_cache_load(llama_ngram_cache & ngram_cache, std::string & filename) {
     std::ifstream hashmap_file(filename, std::ios::binary);
     if (!hashmap_file) {
-        throw std::ifstream::failure("Unable to open file " + filename);
+        return false;
     }
-    llama_ngram_cache ngram_cache;
 
     llama_ngram ngram;
     int32_t     ntokens;
@@ -251,7 +250,7 @@ llama_ngram_cache llama_ngram_cache_load(std::string & filename) {
     }
     GGML_ASSERT(hashmap_file.eof());
 
-    return ngram_cache;
+    return true;
 }
 
 void llama_ngram_cache_merge(llama_ngram_cache & ngram_cache_target, llama_ngram_cache & ngram_cache_add) {

common/ngram-cache.h

@@ -84,9 +84,10 @@ void llama_ngram_cache_draft(
 void llama_ngram_cache_save(llama_ngram_cache & ngram_cache, std::string & filename);
 
 // Load an ngram cache saved with llama_ngram_cache_save.
+// ngram_cache: the ngram cache to load the data into.
 // filename: the path from which to load the ngram cache.
 // returns:  an ngram cache containing the information saved to filename.
-llama_ngram_cache llama_ngram_cache_load(std::string & filename);
+bool llama_ngram_cache_load(llama_ngram_cache & ngram_cache, std::string & filename);
 
 // Merge two ngram caches.
 // ngram_cache_target: the ngram cache to which to add the information from ngram_cache_add.

examples/lookup/lookup-merge.cpp

@@ -33,11 +33,13 @@ int main(int argc, char ** argv){
     }
 
     fprintf(stderr, "lookup-merge: loading file %s\n", args[0].c_str());
-    llama_ngram_cache ngram_cache_merged = llama_ngram_cache_load(args[0]);
+    llama_ngram_cache ngram_cache_merged;
+    GGML_ASSERT(llama_ngram_cache_load(ngram_cache_merged, args[0]));
 
     for (size_t i = 1; i < args.size()-1; ++i) {
         fprintf(stderr, "lookup-merge: loading file %s\n", args[i].c_str());
-        llama_ngram_cache ngram_cache = llama_ngram_cache_load(args[i]);
+        llama_ngram_cache ngram_cache;
+        GGML_ASSERT(llama_ngram_cache_load(ngram_cache, args[i]));
 
         llama_ngram_cache_merge(ngram_cache_merged, ngram_cache);
     }

examples/lookup/lookup-stats.cpp

@@ -47,18 +47,15 @@ int main(int argc, char ** argv){
         const int64_t t_start_draft_us = ggml_time_us();
 
         if (!params.lookup_cache_static.empty()) {
-            try {
-                ngram_cache_static = llama_ngram_cache_load(params.lookup_cache_static);
-            } catch (std::ifstream::failure const &) {
+            if(!llama_ngram_cache_load(ngram_cache_static, params.lookup_cache_static)) {
                 fprintf(stderr, "error: failed to open static lookup cache: %s", params.lookup_cache_static.c_str());
                 exit(1);
             }
         }
 
         if (!params.lookup_cache_dynamic.empty()) {
-            try {
-                ngram_cache_dynamic = llama_ngram_cache_load(params.lookup_cache_dynamic);
-            } catch (std::ifstream::failure const &) {} // if the file does not exist it will simply be created at the end of the program
+            // If the dynamic lookup cache doesn't exist it will be created at the end of the program:
+            llama_ngram_cache_load(ngram_cache_dynamic, params.lookup_cache_dynamic);
         }
 
         t_draft_flat_us += ggml_time_us() - t_start_draft_us;

examples/lookup/lookup.cpp

@@ -57,18 +57,15 @@ int main(int argc, char ** argv){
         llama_ngram_cache_update(ngram_cache_context, LLAMA_NGRAM_MIN, LLAMA_NGRAM_MAX, inp, inp.size(), false);
 
         if (!params.lookup_cache_static.empty()) {
-            try {
-                ngram_cache_static = llama_ngram_cache_load(params.lookup_cache_static);
-            } catch (std::ifstream::failure const &) {
+            if(!llama_ngram_cache_load(ngram_cache_static, params.lookup_cache_static)) {
                 fprintf(stderr, "error: failed to open static lookup cache: %s", params.lookup_cache_static.c_str());
                 exit(1);
             }
         }
 
         if (!params.lookup_cache_dynamic.empty()) {
-            try {
-                ngram_cache_dynamic = llama_ngram_cache_load(params.lookup_cache_dynamic);
-            } catch (std::ifstream::failure const &) {} // if the file does not exist it will simply be created at the end of the program
+            // If the dynamic lookup cache doesn't exist it will be created at the end of the program:
+            llama_ngram_cache_load(ngram_cache_dynamic, params.lookup_cache_dynamic);
         }
 
         t_draft_flat_us += ggml_time_us() - t_start_draft_us;

examples/server/bench/bench.py

@@ -45,6 +45,9 @@ def main(args_in: list[str] | None = None) -> None:
     parser.add_argument("--ubatch-size", type=int, help="physical maximum batch size", required=True)
     parser.add_argument("--scenario", type=str, help="Scenario to run", required=True)
     parser.add_argument("--duration", type=str, help="Bench scenario", required=True)
+    parser.add_argument("--draft", type=int, help="Max. number of additional tokens to draft for lookup decoding", required=False, default=5)
+    parser.add_argument("-lcs", "--lookup-cache-static", type=str, help="Path to optional static lookup cache to use.", required=False, default=None)
+    parser.add_argument("-lcd", "--lookup-cache-dynamic", type=str, help="Path to optional dynamic lookup cache to use. Will be overwritten upon server shutdown.", required=False, default=None)
 
     args = parser.parse_args(args_in)
 
@@ -269,6 +272,11 @@ def start_server_background(args):
     server_args.append('--cont-batching')
     server_args.append('--metrics')
     server_args.extend(['--log-format', "text"])
+    server_args.extend(['--draft', args.draft])
+    if args.lookup_cache_static is not None:
+        server_args.extend(['--lookup-cache-static', args.lookup_cache_static])
+    if args.lookup_cache_dynamic is not None:
+        server_args.extend(['--lookup-cache-dynamic', args.lookup_cache_dynamic])
     args = [str(arg) for arg in [server_path, *server_args]]
     print(f"bench: starting server with: {' '.join(args)}")
     pkwargs = {